Yellow disazo dyes



United States Patent Office meme, fjiifiii 3 399 188 erties but they are inferior to black mixtures made by YELLOW DIAZ0 DYES using the novel yellow d-yes of the present invention. Their Ray Allen Clarke, Puma, and Dale Miner G iffi Jr inferiority is observed in the following tests: (a) Uneven Woodstown, N.J., assignors m E. I. du Pont de Nemours tone durlns the w y from 10 to 300 copies e and Company, Wilmington, DeL, a corporation of 5 original black mixture gives progressively bluer or redder Delaware copies as more copies are made. (b) Said prior art yellow N0 Dl'awlllg- 1964, 413,310 dyes exhibit weakness, as observed in the black copies, 7 C (CL 260-152) as compared with black mixtures made from equal amounts of the novel yellow dyes of the present invention. AFSTRACT OF THE DISCLOSURE 10 -It has been discovered that the yellow dyes of the pres- Yellow drsazo dyes of the structure ent invention are free of the heretofore described well CE: /CH3 CH3 CH:

R1 /C=CHN=N ,CH2N=NCH=C I R1 IFT Y Y N R: I11;

and the acid salts of these dyes are useful in black known prior art shortcomings and, in addition, possess hectograph and spirit inks. Typical black dyes include a 2 highly desirable properties which have overcome problems dye or dye salt of the above structure, Crystal Violet and heretofore existing in the manufacture and use of hecto- Victoria Blue B, or a dye or dye salt of the above strucgraph blacks. The novel yellow dyes of the present inventure, Crystal Violet and Victoria Pure Blue BO. tion exhibit the following desirable properties as observed in the black mixtures:

(a) hydrolytic stability at high temperatures during manufacture of the spirit blacks,

(b) thermal stability during high temperature coating of the carbon paper sheets,

(c) even tone throughout the copy run, dissolves rapidly,

(d) good strength of the yellow component, and

(e) good compatibility with basic dyes and with hectograph vehicles.

This invention is directed to novel yellow disazo dyes and their use in hectograph or spirit inks, particularly in the production of spirit blacks.

The black inks generally used in hectograph systems consist essentially of mixtures of a yellow Chrysoidine dye with basic dyes such as Crystal Violet, Brilliant Green and Victoria Blue. The resulting black mixtures, however, exhibit unsatisfactory properties which are caused by the yellow component. For example, they show a shift in More p y, the novel Yellow y of this invenshade toward the blue or red as the copy run continues. tion are y fetraZOtiZiIlg a 4,4'-diaminodiphenylmfith- Other shortcomings of the known blacks include their 3116 f t Structure;

hydrolytic instability, their thermal instability, and the tendency of their yellow component to transfer from copy H2N CH 2 images to adjacent paper during storage. Although these deficiencies are known to be caused by Chrysoidine dyes, identified as C.I. 11,270 and Cl. 11,320, attempts in the wherein Y is H, F, C1 or Br, a C alkyl group, methoxy past to find a superior substitute have been unsuccessful. or ethoxy, followed 'by coupling inacidic medium to a German Patent 1,044,588 represents the closest prior 2-methyleneindoline of the structure art and in Example 6 discloses a copy black made from CH3 malachite green, methyl violet, fuchsine and a yellow azo dye made by coupling diazotized aniline to 1,3,3-trimethyl- Z-methyleneindoline (Fischers Base); this yellow dye, when tested in various black mixtures with basic blues, violets and greens, always transfers' from copy images to adjacent paper upon storage even for short periods of time such as 8 to 24 hours. These yellow transfer markwherein R is H, F, Cl, Br, methoxy or ethoxy, and R ings are, of course, objectionable in the trade. This German is methyl or phenyl. The rseulting disazo dye is isolated patent discloses other yellows made from Fischer' Base either in baseform or as its acid salt. and tetrazotized aryl diamines such as diaminodiphenyl- The novel dyes of the present invention, in free base oxide and benzidine. Spirit Blacks made from these yelform, have the structure:

CH3 CH3 CH3 CH3 V R1 /C=CH-N=NCH -N=N-oH=o\ I a, N Y Y low dyes do not exhibit the objectionable transfer propwherein R R and Y are as heretofore defined.

3,399,188 3 4 Embodiments of this invention include: part (a) with, respectively, 234 parts of 4,4-diamino- 3,3'-difluorodiphenylmethane or with 356 parts of 4,4- diamino 3,3 dibrornodiphenylmethane, yellow hectograph dyes are obtained. 5 (0) When the procedure of part (a) is repeated except that the 4,4'-diaminodiphenylmethane is replaced by 226 parts of 4,4-diamino-3,3-dirnethyldiphenylmethane, a yellow dye having similar properties is obtained. Likewise, similar dyes are obtained when chemically equivalent amounts of 4,4'-diamino3,3'-diethyldiphenylmethane or of 4,4-diamino-3,3'-dibutyldipheny1methane are employed as the aromatic diamine in this example.

(d) When the diamine used in part (a) of this example is replaced by 258 parts of 4,4-diamino-3,3-dimethoxy- EXAMPLE I diphenylmethane, or by 286 parts of 4,4'-diamino-3,3'- To a mixture of 3000 P of Water and 513 Parts diethoxydiphenylrnethane yellow dyes having similar proof 37% hydrochloric acid are added 198 parts (1 mole) parties are Obtainecp of 4,4'-diaminodiphenylmethane. The mixture is stirred until all the diamino compound dissolves. To the mixture is added ice sufficient to lower the temperature to 0-5 (e) The yellow dye of part (a) of the present example C. Tetrazotization is accomplished by the addition of a may be i olated as the f b e if desired, At the end solution of 144 parts (2.09 moles) sodium nitrite in 500 of the coupling reaction, as shown by the disappearance (a) A black dye mixture comprising a novel dye as heretofore described intimately mixed with basic dyes of the triarylmethane series.

(b) A hectograph ink comprising the dye mixture of (a) intimately mixed with a hectographic ink vehicle.

(c) A process for the production of hectograph carbon papers wherein the ink of (b) is evenly coated on the surface of paper.

(d) A process for the spirit copying of images transfer- 10 red to a master sheet from a carbon paper of (c) Representative examples further illustrating the present invention follow.

Yellow dyes as free bases parts of water over a period of 5-20 minutes, mainof a test for active diazonium compounds, bases such as taining a temperature of 05 C. by the addition of i sodium hydroxide, sodium carbonate or ammonia are as necessary. An excess of nitrous acid as shown by a added to the reaction slurry to adjust the pH to a value reaction on starch-iodide paper is maintained for 10-20 8 or higher. This pH is maintained by addition of more minutes by small additions of sodium nitrite solution if base as necessary until a steady pH value is obtained, necessary. The excess nitrous acid is then removed by showing that no more acid salt of the dye remains'to be adding sulfamic acid until the reaction mixture gives no neutralized. The free color base is isolated by filtration test for nitrous acid with starch-iodide papers. To the and is washed free of salts with water.

mixture are added 348 parts (2.01 moles) of Fischers Alternatively, after the dye is isolated as the dihydro- Base (1,3,3-trimethyl-2-methyleneindoline) over a 30 to chloride salt as in Example 1(a) it is re-slurried in water 45 minute period, with temperature being maintained at followed by addition of bases as above to convert the 0-10 throughout. Sodium carbonate, as a 10-20% dye salt to the free base, which is isolated by filtration aqueous solution, is added to maintain a pH in the range and washing.

3.5-5.0 until coupling is complete as shown by the If desired, dye salts utilizing acids other than hydroabsence of a test for diazo compound, e.g. by streaking a ehlorie may be employed. Other acids include sulfuric, sample of the reaction mass on a filter paper wet with Phosphoric, P-tohleneslllfonie d the like which are realkaline H-Acid solution. The dye precipitates during the acted With the y in its free base form For use in hectocoupling to form an orange slurry. During the coupling, graph inks the hydrochloride salts are Preferredthe temperature is allowed to rise freely. Coupling is Although the 1101/61 Yellow dyes y he used as free usually complete in two to four hours. When coupling bases in tsf P s this form is hot Preferred is complete, 37% hydrochloric acid is added to the mass cause of the hlgh solublhty 0f the y ases in the oil in an amount sufficient to make a concentration of 0.5 Vehiclesto 1.0% HCl in the mass. The mass is heated to -10 45 MP E II C. for one to two hours to insure formation of the di- I the process of Example 1(a) the coupling c hydrochloride of the y The y, after cooling to ponent 1,3,3-trimethyl-Z-methyleneindoline is replaced by 25i5 (3., is fi e and the filter C is Washed t 436 parts of S-ethoxy-1,3,3-trimethyl-2-methyleneindoline. 2000 to 3000 parts of 0.3-0.5 aqueous hydrochloric A strong spirit soluble yellow dye is obtained. Likewise, acid soluti The filter cake y be dried, but is usually v.50 a chemically equivalent amount of the corresponding 5- used as a wet paste. The dye thus obtained has the strucmethoxy indoline coupler gives a yellow dye having simiture: lar properties.

CH3 CH3 CH3 CH3 /C=CHN=N-CH;N=N-CH=O 21101 (EH: (3113 Analysis of the yellow dye of Example 1(a) (b) In the process of Example 1(a) the 1,3,3-trimeth- Drying the yellow dye of Example H3) at for yI-Z-methylenemdoline is replaced by 417 parts 4-chloro- 24 hours yields a product containing 3.3% water as deter- 1,3,3 mmethyl 2 methylenelhdohhe and, p

mined by titration with Karl Fischer reagent. Titration of twely, Parts chlol'o 3 trimethyl a Sample of this dried dye with Standard sodium hydrox 65 methylenemdolme to give strong, spirit soluble yellow ide shows it to contain 10.8% hydrochloric acid. The dyescalculated hydrochloric acid content for the dye M ures of yellow dyes are obtained by using mixed C H N HC 4,4 diaminodiphenylmethanes which are prepared by 37 aa 6 condensing two moles of a mixture of aromatic monocontaining 33% Water is 110 4% amines with one mole of formaldehyde in acidic medium 1 w the procedure f pal-t (a) f this example by known methods. Typical amines used in this reaction is followed except that the 4,4'-diaminodiphenylmethane are the following: a l i -fluoroanii replaced b 267 parts f 4,4'-di i -3,3'.di h1 line, o-bromoaniline, o-anisidine, o-phenetidine, o-toluidiphenylmethane, a redder yellow dye is obtained which dine, o-ethylaniline, o-propylaniline, o butylaniline. Likehas similar properties. Also, by replacing the diamine in wise any of the diamines or mixtures of any of the diamines employed herein, such as a 50:50 mixture of 4,4- diaminodiphenylmethane and 4,4'-diamino-3,3'dimethyl diphenylmethane may be tetrazotized and coupled with any of the Fischers base compounds named above to obtain yellow dyes having excellent properties for use in hectograph inks.

EXAMPLE III (a) To an open, heated vessel equipped with an eflicient agitator are added Crystal Violet (C.I. 42,555) wet filter cake equivalent to 74 parts of 100% dye, a quantity of the wet yellow dye of Example 1(a) equivalent to 115 parts of dry dye, and Victorian Blue B (C.I. 44,045) wet filter cake equivalent to 30 parts of 100% dye. The mixture is heated with stirring to a temperature of 100l C. During the heating the dyes melt to form a homogeneous tar. Heating at 100115 C. is continued until the tar becomes so thick as to be just pourable. The molten, thickened tar is poured into a pan and dried at 8095 C. preferably in vacuum, to a constant weight. The dry dye is finely pulverized for use in preparing hectograph inks.

(1b) In the process of Example III(a) the yellow dye is replaced by a like amount of the yellow dye prepared by the procedure of Example I(b), used as a water-wet filter cake. An excellent hectograph black is obtained.

(c) In the process of Example III(a) the 30 parts of Victorian Blu-e B is replaced by 'a like amount of Victorian Pure Blue B0 (C1. 42,595) or of Brilliant Green (C.I. 42,040) to provide hectograph blacks having excellent working properties.

(d) Following the procedure of Example III(a) a black is prepared from 115 parts of the yellow dye of Example I(c), 60-70 parts of methyl violet (Cl. 42,535) and to parts of Brilliant Green (C.I. 42,040).

A similar black hectograph dye is obtained when the yellow dye of Example He) is replaced by 115 parts of the yellow dye of Example II(a).

EXAMPLE IV Preparation of spirit blacks by dry-mixing of component dyes (a) Fifty parts of the dry, yellow dye of Example 1(a) are mechanically mixed with parts of dry Crystal Violet (C.I. 42,555) and 20 parts of dry Victorian Blue B (C.I. 44,045). Two to five percent or more of mineral or other oil based on total dye weight may be added as an anti-dusting agent. This mixture is used to prepare hectograph inks in the same manner as mixtures prepared by melting the wet dyes together and drying.

(b) When Methyl Violet (C.I. 42,535) is used in place of Crystal Violet, or when Victorian Pure Blue BO (C.I. 42,595) is used in place of Victorian Blue B in part (a) of the present example excellent spirit black dyes are obtained. The amounts of dyes used may, of course, be varied depending on the degree of red-ness or greenness desired in the final product.

It is to be understood that other basic triarylmethane dyes may be used in Examples III and IV in lieu of those named therein. For instance the following dyes may be used in mixture with the novel yellow dyes of the present invention in order to provide hectograph dyes in varying shades of blue, black and violet: C.I. 42,000, C.I.

Basic Green 4; Cl. 42,025, C.I. Basic Blue 1; Cl. 42,500, C.I. Basic Red 9; Cl. 42,510, C.I. Basic Violet 14; Cl. 42,600, C.I. Basic Violet 4; CI. 44,040, C.I. Basic Blue 11.

EXAMPLE V Preparation of a typical hectograph ink composition In a heated vessel at a temperature in the range of 85120 C. are placed 65 parts by weight of Carnauba wax, 157 parts of petroleum jelly (Vaseline), 67 parts of mineral oil SAE No. 30, and 10 parts of parafiin wax. This mixture rafter melting, is stirred until it is homogeneous.

To 100 parts of the molten wax-oil mixture is added an equal 'weight of the hectograph dye of Example III(a) with agitation to obtain complete wetting of the dye by the vehicle. The resulting hectograph ink is then ground at l20 C. in a ball mill to give a well dispersed suspension of finely ground black dye in the vehicle. The resulting suspension is useful for application in the trade, as described in Example VI.

The amount of dye employed per part of the wax-oil vehicle may vary from about 0.75 to 1.2 parts. Less dye than about 0.75 part/part of vehicle will give weak hectograph copies. More dye than about 1.2 parts/part of vehicle will give viscosities too high to be useful in the trade. Viscosities of hectograph inks used in the trade vary between about to 600 centipoises.

In lieu of ball milling, employed in the present example, one may roller mill the ink, or the ink may be first ball milled 'folowed by roler milling. In any case, the milling is continued until the desired degree of fineness is reached as determined by a grit gauge or by any other means common to the art of grinding hectograph inks.

The hectograph black dye of Example III(a) may be replaced in the present example by any other hectograph dyes disclosed herein or by mixtures thereof.

EXAMPLE VI Preparation of the hectograph carbon sheet The molten hectograph ink of Example V is applied while hot to a moving sheet of paper and the ink thickness is regulated by means of a doctor bar or knife, so that a uniform coating about 0.0005 inch thick is obtained. On cooling, the ink solidifies and the carbon paper is ready for further processing. Normally, the coated sheet thus prepared is assembled with a protective sheet and a master sheet, which assembly is cut to convenient dimensions and is ready for use in duplication processes.

If desired, the cooled carbon paper prior to further processing, is given one more coating of a clear wax which protects the dye-containing coat from abrasion and also prevents transfer of the dye to the hands of a person handling the coated sheet.

It is to be understood that hectograph inks made from other dyes and dye mixtures described in the present in vention may be employed to coat paper which is then referred to as carbon paper.

EXAMPLE VII Useof the hectograph carbon sheet in duplication Images of symbols are recorded on the master sheet, assembled as described in Example VI, by writing, drawing, typing, etc., as is well known in the trade. The pressure applied by such operations causes the wax-dye dispersion (hectograph ink) to transfer to the master sheet as a reverse or negative image of the symbols used. The master is now separated and then pressed firmly against sheets of copy paper which have been wet with a film of spirit solvent, usually lower alcohols. Dye on the negative master sheet dissolves in the solvent film and transfers to the copy sheet where it appears as a positive reproduction of the original symbols inscribed on the master sheet.

The preceding representative examples may be varied within the scope of the present total specification disclosure, as understood and practiced by one skilled in the art, to achieve essentially the same results. For example, in Example III, the practical percentage range, by weight, of components may be defined as 30 to 40% Crystal Violet; 40 to 60% of the yellow and 5 to 20% of the blue.

As many apparently widely dilferent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof except as defined in the appended claims.

7 8 The embodiments of the present invention in which an wherein R is selected from the group consisting of H, F, exclusive property 01' privilege is claimed are as follows: Cl, Br, methoxy and ethoxy; R is selected for the group 1. Dyes, in free base form, having the structure: consisting of methyl and phenyl; and Y is selected from CH3 CH3 CH3 CH3 C C R; l C=CHN=N CH N=NCH=C R1 t Y Y Ra Ra wherein R is selected from the group consisting of H, the group consisting of H, F, Cl, Br, C alkyl, methoxy F, Cl, Br, methoxy and ethoxy; R is selected from the 1D and ethoxy.

group consisting of methyl and phenyl; and Y is selected 4. The acid salts of claim 3 in which the acid is selected from the group consisting of H, F, Cl, Br, C alkyl, from the group consisting of hydrochloric, sulfuric, phosmethoxy and ethoxy. phoric and p-toluenesulfonic acids.

2. The dye of claim 1 in which R is H, R is methyl 5. The acid salts of claim 4 in which R is H, R is and Y is H. 20 methyl and Y is H.

3. Acid salts of dyes which, in free base form, have 6. The acid salts of claim 3 in which the acid is hydrothe structure: chloric acid.

CH3 CH1 CH3 CH3 R1 c=cn-N=N-@crn-@-N=N-on=o l R1 Y Y r R2 R1 7. The dye:

CH3 CH3 CH3 CH3 C=CHN=NCHr- N=NCH=C 21101 N JJHIS (5H3 References Cited FOREIGN PATENTS 1,044,588 5/ 1959 Germany.

CHARLES E. PARKER, Primary Examiner.

D. PAPUGA, Assistant Examiner. 

